Improvement in brakes for hoisting-machines



' E. BENJAMIN. Braks for Hoisting Machine-s.

Pa t ented Oct. 13,1874.

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UNITED STATES PATENT OEEIoE.

EDWIN BENJAMIN,.OF CHICAGO, ILLINOIS, ASSIGNOR TO SAMUEL A. KENNEDY, OF SAME PLACE.

IMPROVEMENT IN BRAKES FOR HOISTING-MACHINES.

Specification forming part of Letters Patent No. 155,822, dated October 13, 1874; application filed June 25, 1874. I

. Illinois, have invented a new and useful Improvement in Brakes for Hoisting-Machines, of which the following is a specification:

The object of the present invention is to provide a simple, cheap,'and more effectual brake to be used in controlling the movement of the platforms of hoisting-machines, which are toelevate freight and other articles from one floor to another in warehouses and build- 1ngs.

The nature of the invention consists in the combination of two brake-levers with connectingrods, a screw operated by a belt or cord, and a wrist-wheel, whereby, when the screw is operated, the wrist-wheel is turned so as to draw on the connecting-rods, and force the brake-levers against a friction-wheel, which, when retarded, checks the movement of the platform.

In the drawings, Figure l is an elevation of my improvement in brakes attached to a hoisting-machine, Fig. 2, a vertical section thereof on line a; m, Fig. 1; Fig. 3, an elevation of one of the brake-levers removed from the other part of the machine.

A represents one of the upright frame-pieces of a hoisting-machine, which may be of any size or shape desirable, according to the form or style of the machine to be built. 13 represents the sheavewheel, which in the ordinary machine carries a rope for elevating the ordinary platform. This wheel is attached to the same journal or shaft n as the fllClilOIlWll8G1 O, and, consequently, rotates with it, the journal n having a firm bearing in the upright A, as shown at Fig. 1. A cross-tree, T, Figs. 1 and 2, is rigidly secured to the uprights A, and to its ends are pivoted, at 'r, brake-levers D D, which are provided on their sides with curved surfaces corresponding to the periphery of those parts of the friction-wheel O with which they come in contact, as shown at Figs. 1 and 3. To the lower ends of these brake.- levers are pivoted, at a, connecting-rods F, the opposite ends of which are pivoted to wrists c c on a wheel, E. This wheel is pivoted to a stud, S, projecting out from the upright A, and its periphery, or a portion thereof, so much as is necessary, is provided with teeth suitable to engage a screw, Gr, on a shaft, H, so that, when the screw is turned by'sheave-wheel J, or other similar device, the wheel E will be partially rotated, and draw or push upon the brake-levers D D, (by means of the rods F,) as the case may require, to set them to or from "the wheel 0. Any suitable bearings, I, hav' ing seats on a cross-tree, are used to support the shaft H, and any ordinary rope or cord, m, may be used to rotate the sheave J.

In the foregoing I have described several parts of a hoisting-machine which I do not claim to have invented; but have been thus particular to enable a builder of machines to understand how my device operates and effects the stoppage of the machine. v

In practice it may be necessary to coil a rope two or more times round the sheave J, in order to turn it.

The operation is simple, requiring only that the rope m be drawn in one direction to bring the levers D onto the Wheel U, and drawn in an opposite direction to release the levers or brake.

Having thus described my invention, what I claim, and desire to secure by Letters Patent of the United States, is-

The combination of the wheel E, connecting-rods F F, brake-levers D D, friction-wheel U, and shaft H with its screw-thread G and sheave-wheel J, substantially as and for the purpose set forth.

EDWIN BENJAMIN.

Witnesses:

JOHN H. ELLIOTT, JOHN KENNEDY. 

